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1.
Sci Bull (Beijing) ; 69(13): 2089-2098, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38777681

RESUMEN

Tactile sensing provides robots the ability of object recognition, fine operation, natural interaction, etc. However, in the actual scenario, robotic tactile recognition of similar objects still faces difficulties such as low efficiency and accuracy, resulting from a lack of high-performance sensors and intelligent recognition algorithms. In this paper, a flexible sensor combining a pyramidal microstructure with a gradient conformal ionic gel coating was demonstrated, exhibiting excellent signal-to-noise ratio (48 dB), low detection limit (1 Pa), high sensitivity (92.96 kPa-1), fast response time (55 ms), and outstanding stability over 15,000 compression-release cycles. Furthermore, a Pressure-Slip Dual-Branch Convolutional Neural Network (PSNet) architecture was proposed to separately extract hardness and texture features and perform feature fusion. In tactile experiments on different kinds of leaves, a recognition rate of 97.16% was achieved, and surpassed that of human hands recognition (72.5%). These researches showed the great potential in a broad application in bionic robots, intelligent prostheses, and precise human-computer interaction.

2.
J Phys Chem Lett ; 15(22): 5862-5867, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38804506

RESUMEN

An artificial tactile receptor is crucial for e-skin in next-generation robots, mimicking the mechanical sensing, signal encoding, and preprocessing functionalities of human skin. In the neural network, pressure signals are encoded in spike patterns and efficiently transmitted, exhibiting low power consumption and robust tolerance for bit error rates. Here, we introduce a highly sensitive artificial tactile receptor system integrating a pressure sensor, axon-hillock circuit, and neurotransmitter release device to achieve pressure signal coding with patterned spikes and controlled neurotransmitter release. Owing to the heightened sensitivity of the axon-hillock circuit to pressure-mediated current signals, the artificial tactile receptor achieves a detection limit of 10 Pa that surpasses the human tactile receptors, with a wide response range from 10 to 5 × 105 Pa. Benefiting from the appreciable pressure-responsive performance, the potential application of an artificial tactile receptor in robotic tactile perception has been demonstrated, encompassing tasks such as finger touch and human pulse detection.


Asunto(s)
Presión , Tacto , Humanos , Robótica , Receptores Artificiales/química , Receptores Artificiales/metabolismo , Neurotransmisores/química
3.
J Nat Med ; 78(2): 355-369, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38265611

RESUMEN

Chemotherapy is still a prevalent strategy for clinical lung cancer treatment. However, the inevitable emerged drug resistance has become a great hurdle to therapeutic effect. Studies have demonstrated that the primary cause of drug resistance is a decrease in the chemotherapeutic medicine concentration. Several lectins have been confirmed to be effective as chemotherapy adjuvants, enhancing the anti-tumor effects of chemotherapy drugs. Here, we combined phytohemagglutinin (PHA), which has been reported possess anti-tumor effects, with chemotherapy drugs Cisplatin (DDP) and Adriamycin (ADM) on lung cancer cells to detect the sensitivities of PHA as a chemotherapy adjuvant. Our results demonstrated that the PHA significantly enhanced the sensitivity of lung cancer cells to DDP and ADM, and Western blot showed that PHA combined with DDP or ADM enhance cytotoxic effects by inhibiting autophagy and promoting apoptosis. More importantly, we found PHA enhanced the chemotherapeutic drugs cytotoxicity by changing the cell membrane to increase the intracellular chemotherapeutic drugs concentration. Besides, the combination of PHA and ADM increased the ADM concentration in the multidrug-resistant strain A549-R cells and achieved the drug sensitization effect. Our results suggest that PHA combined with chemotherapy can be applied in the treatment of lung cancer cells and lung cancer multidrug-resistant strains, and provide a novel strategy for clinical tumor chemotherapy and a new idea to solve the problem of drug resistance in clinical lung cancer.


Asunto(s)
Antineoplásicos , Neoplasias Pulmonares , Phaseolus , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Fitohemaglutininas/farmacología , Fitohemaglutininas/metabolismo , Fitohemaglutininas/uso terapéutico , Phaseolus/metabolismo , Permeabilidad de la Membrana Celular , Resistencia a Antineoplásicos , Línea Celular Tumoral , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Doxorrubicina/farmacología , Doxorrubicina/uso terapéutico , Apoptosis , Proliferación Celular
4.
ACS Appl Mater Interfaces ; 15(41): 48683-48694, 2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37812741

RESUMEN

Flexible pressure sensors are increasingly sought after for applications ranging from physiological signal monitoring to robotic sensing; however, the challenges associated with fabricating highly sensitive, comfortable, and cost-effective sensors remain formidable. This study presents a high-performance, all-fabric capacitive pressure sensor (AFCPS) that incorporates piezoelectric nanofibers. Through the meticulous optimization of conductive fiber electrodes and P(VDF-TrFE) nanofiber dielectric layers, the AFCPS exhibits exceptional attributes such as high sensitivity (4.05 kPa-1), an ultralow detection limit (0.6 Pa), an extensive detection range (∼100 kPa), rapid response time (<26 ms), and robust stability (>14,000 cycles). The sensor's porous structure enhances its compressibility, while its piezoelectric properties expedite charge separation, thereby increasing the interface capacitance and augmenting overall performance. These features are elucidated further through multiphysical field-coupling simulations and experimental testing. Owing to its comprehensive superior performance, the AFCPS has demonstrated its efficacy in monitoring human activity and physiological signals, as well as in discerning soft robotic grasping movements. Additionally, we have successfully implemented multiple AFCPS units as pressure sensor arrays to ascertain spatial pressure distribution and enable intelligent robotic gripping. Our research underscores the promising potential of the AFCPS device in wearable electronics and robotic sensing, thereby contributing significantly to the advancement of high-performance fabric-based sensors.


Asunto(s)
Nanofibras , Procedimientos Quirúrgicos Robotizados , Robótica , Dispositivos Electrónicos Vestibles , Humanos , Nanofibras/química , Presión
5.
J Cell Commun Signal ; 17(4): 1417-1433, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37548811

RESUMEN

An increasing number of studies have documented atypical protein kinase C isoform ι (PKCι) as an oncoprotein playing multifaceted roles in pancreatic carcinogenesis, including sustaining the transformed growth, prohibiting apoptosis, strengthening invasiveness, facilitating autophagy, as well as promoting the immunosuppressive tumor microenvironment of pancreatic tumors. In this study, we present novel evidence that PKCι overexpression increases STAT3 phosphorylation at the Y705 residue while decreasing STAT3 phosphorylation at the S727 residue in pancreatic cancer cells. We further demonstrate that STAT3 phosphorylation at Y705 and S727 residues is mutually antagonistic, and that STAT3 Y705 phosphorylation is positively related to the transcriptional activity of STAT3 in pancreatic cancer cells. Furthermore, we discover that PKCι inhibition attenuates STAT3 transcriptional activity via Y705 dephosphorylation, which appears to be resulted from enhanced phosphorylation of S727 in pancreatic cancer cells. Finally, we investigate and prove that by modulating the STAT3 activity, the PKCι inhibitor can synergistically enhance the antitumor effects of pharmacological STAT3 inhibitors or reverse the anti-apoptotic side effects incited by the MEK inhibitor, thereby posing as a prospective sensitizer in the treatment of pancreatic cancer cells.

6.
Int Immunopharmacol ; 120: 110322, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37269742

RESUMEN

Leukocyte phytohemagglutinin (PHA-L) is a tetrameric isomer of phytohemagglutinin (PHA) purified from the red kidney bean (Phaseolus vulgaris) and is a well-known human lymphocyte mitogen. Due to its antitumor and immunomodulatory effects, PHA-L may serve as a potential antineoplastic agent in future cancer therapeutics. However, various negative consequences of PHA have been reported in the literature as a result of the restricted acquisition methods, including oral toxicity, hemagglutinating activity, and immunogenicity. There is a critical need to explore a new method to obtain PHA-L with high purity, high activity and low toxicity. In this report active recombinant PHA-L protein was successfully prepared by Bacillus brevius expression system, and the antitumor and immunomodulatory activities of recombinant PHA-L were characterized by in vitro and in vivo experiments. The results showed that recombinant PHA-L protein had stronger antitumor effect, and its anti-tumor mechanism was realized through direct cytotoxicity and immune regulation. Importantly, compared with natural PHA-L, the recombinant PHA-L protein showed the lower erythrocyte agglutination toxicity in vitro and immunogenicity in mice. Altogether, our study provides a new strategy and important experimental basis for the development of drugs with dual effects of immune regulation and direct antitumor activity.


Asunto(s)
Bacillus , Neoplasias , Phaseolus , Humanos , Animales , Ratones , Fitohemaglutininas/farmacología , Phaseolus/metabolismo , Bacillus/metabolismo , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/metabolismo , Apoptosis
7.
Nano Lett ; 23(11): 4974-4982, 2023 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-37273232

RESUMEN

In biological neural networks, chemical communication follows the reversible integrate-and-fire (I&F) dynamics model, enabling efficient, anti-interference signal transport. However, existing artificial neurons fail to follow the I&F model in chemical communication, causing irreversible potential accumulation and neural system dysfunction. Herein, we develop a supercapacitively gated artificial neuron that mimics the reversible I&F dynamics model. Upon upstream neurotransmitters, an electrochemical reaction occurs on a graphene nanowall (GNW) gate electrode of artificial neurons. Charging and discharging the supercapacitive GNWs mimic membrane potential accumulation and recovery, realizing highly efficient chemical communication upon use of acetylcholine down to 2 × 10-10 M. By combining artificial chemical synapses with axon-hillock circuits, the output of neural spikes is realized. With the same neurotransmitter and I&F dynamics, the artificial neuron establishes chemical communication with other artificial neurons and living cells, holding promise as a basic unit to construct a neural network with compatibility to organisms for artificial intelligence and deep human-machine fusion.


Asunto(s)
Inteligencia Artificial , Biónica , Humanos , Modelos Neurológicos , Neuronas/fisiología , Sinapsis/fisiología , Neurotransmisores
8.
ACS Appl Mater Interfaces ; 15(12): 15884-15892, 2023 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-36929869

RESUMEN

Flexible positive pressure sensors have been studied extensively and have been used in a lot of scenarios. However, negative pressure detection is also in demand in some scenarios, such as fluid mechanics analysis, air pressure sensing, and so on. Flexible wearable sensors that can detect both positive and negative pressures will greatly broaden the application field. In this paper, we report a flexible highly sensitive ionic gel (IG) pressure sensor, which is simple and of low cost to prepare and can reliably detect a large pressure range from -98 to 100 kPa under an atmospheric pressure of about 982 hPa. The IG dielectric layer is composed of polyvinyl alcohol and phosphoric acid with a random microstructure of sandpaper inversion. The sensor exhibits flexibility, cycling stability, and high sensitivity under both negative and positive pressures (S = 84.45 nF/kPa for the negative pressure section, S = 25.61 nF/kPa for the positive pressure section). These sensors could be worn on the body not only to test breathing and pulse but also to measure air pressure for estimating the altitude, showing that the flexible full-pressure sensors have a wider application range in wearable electronics.

9.
J Acoust Soc Am ; 152(3): 1539, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36182319

RESUMEN

The effect of perforating the honeycomb walls of a honeycomb sandwich panel on the dynamic bending stiffness and sound transmission loss of the panel is investigated. The dynamic bending stiffness and sound transmission loss of several sandwich panels with different cores are calculated using a semi-analytical method, and the static bending stiffness and flatwise stiffness of these structures are also analyzed with the finite element method. Furthermore, the influences of the honeycomb shape, the hole shape of the perforated honeycomb wall, the number of perforations, and the wall thickness on the vibro-acoustic and mechanical properties of the sandwich panel are investigated. The results show that the static mechanical performance of the sandwich panel quickly reaches a high level when the ratio of honeycomb wall thickness to length t/l is about 5.3 × 10-3 and a square hole in the honeycomb wall can bring superior characteristics of "high static and low dynamic properties," significantly improving the sound insulation of the sandwich panel. This study makes an effective reference for the optimized design of the innovative sandwich structure in practical applications.

10.
BMC Biotechnol ; 22(1): 32, 2022 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-36309691

RESUMEN

BACKGROUND: Leukocyte phytohemagglutinin (PHA-L), derived from the L4 tetramer of PHA, has been frequently employed as a mitogen to induce T lymphocyte proliferation in vitro. The biological application of PHA-L in cancer diagnosis and treatment has gained traction in recent years. However, it has been noted that PHA-L obtained using traditional procedures has a massive amount of impurities or toxic components, which interfere with the activity of PHA-L. Preparation of a monoclonal antibody against active PHA-L is a significant tool for studying PHA-L's function and therapeutic potential. RESULTS: We successfully prepared monoclonal antibodies against the active components of PHA-L based on the whole PHA-L protein as an antigen, and found that monoclonal antibody 3C1C6G11 can be employed in western blot, immunofluorescence, and immunohistochemistry detection. Importantly, preliminary result shows that the mAb 3C1C6G11 may prevent PHA-L-induced cell aggregation and AICD (activation-induced cell death). CONCLUSIONS: The monoclonal antibody mAb 3C1C6G11 prepared in this study can be used as an effective tool for detecting PHA-L active components, investigating PHA-L's function and antineoplastic application.


Asunto(s)
Anticuerpos Monoclonales , Phaseolus , Fitohemaglutininas/farmacología , Activación de Linfocitos
11.
Nanomaterials (Basel) ; 12(9)2022 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-35564203

RESUMEN

Flexible capacitive pressure sensors have been widely used in electronic skin, human movement and health monitoring, and human-machine interactions. Recently, electronic textiles afford a valuable alternative to traditional capacitive pressure sensors due to their merits of flexibility, light weight, air permeability, low cost, and feasibility to fit various surfaces. The textile-based functional layers can serve as electrodes, dielectrics, and substrates, and various devices with semi-textile or all-textile structures have been well developed. This paper provides a comprehensive review of recent developments in textile-based flexible capacitive pressure sensors. The latest research progresses on textile devices with sandwich structures, yarn structures, and in-plane structures are introduced, and the influences of different device structures on performance are discussed. The applications of textile-based sensors in human wearable devices, robotic sensing, and human-machine interaction are then summarized. Finally, evolutionary trends, future directions, and challenges are highlighted.

12.
Sensors (Basel) ; 22(7)2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-35408265

RESUMEN

Flexible pressure sensors have received extensive attention in recent years due to their great importance in intelligent electronic devices. In order to improve the sensing performance of flexible pressure sensors, researchers are committed to making improvements in device materials, force-sensitive interfaces, and device structures. This paper focuses on the force-sensitive interface engineering of the device, which listing the main preparation methods of various force-sensitive interface microstructures and describing their respective advantages and disadvantages from the working mechanisms and practical applications of the flexible pressure sensor. What is more, the device structures of the flexible pressure sensor are investigated with the regular and irregular force-sensitive interface and accordingly the influences of different device structures on the performance are discussed. Finally, we not only summarize diverse practical applications of the existing flexible pressure sensors controlled by the force-sensitive interface but also briefly discuss some existing problems and future prospects of how to improve the device performance through the adjustment of the force-sensitive interface.

14.
Cell Prolif ; 54(11): e13130, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34599546

RESUMEN

OBJECTIVES: It is imperative to develop efficient strategies on the treatment of prostate cancer. Here, we constructed multifunctional nanoparticles, namely AS1411@MPDA-DTX (AMD) for targeted and synergistic chemotherapy/photothermal therapy of prostate cancer. MATERIALS AND METHODS: Mesoporous polydopamine (MPDA) nanoparticles were prepared by a one-pot synthesis method, DTX was loaded through incubation, and AS1411 aptamer was modified onto MPDA by the covalent reaction. The prepared nanoparticles were characterized by ultra-micro spectrophotometer, Fourier transform infrared spectra, transmission electron microscope, and so on. The targeting ability was detected by selective uptake and cell killing. The mechanism of AMD-mediated synergistic therapy was detected by Western blot and immunofluorescence. RESULTS: The prepared nanoparticles can be easily synthesized and possessed excellent water solubility, stability, and controlled drug release ability, preferentially in acidic context. Based on in vitro and in vivo results, the nanoparticles can efficiently target prostate cancer cells, promote DTX internalization, and enhance the antitumor effects of chemo-photothermal therapy strategies under the NIR laser irradiation. CONCLUSIONS: As a multifunctional nanoplatform, AS1411@MPDA-DTX could efficiently target prostate cancer cells, promote DTX internalization, and synergistically enhance the antiprostate cancer efficiency by combining with NIR irradiation.


Asunto(s)
Docetaxel/farmacología , Doxorrubicina/farmacología , Indoles/farmacología , Polímeros/farmacología , Neoplasias de la Próstata/tratamiento farmacológico , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos/métodos , Humanos , Masculino , Nanopartículas/uso terapéutico , Terapia Fototérmica/métodos , Porosidad/efectos de los fármacos
15.
Front Oncol ; 11: 711207, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34621671

RESUMEN

Hypoxia is a common feature of solid tumors including stomach cancer (SC) and is closely associated with cancer malignant progression. N6-methyladenosine (m6A), a common modification on RNA, is involved in the regulation of RNA fate and hypoxic responses in cancers. However, the interaction between m6A reader insulin-like growth factor-II mRNA-binding protein 3 (IGF2BP3) and SC hypoxic microenvironment is poorly defined. In the present study, expression levels of IGF2BP3 and hypoxia inducible factor-1α (HIF1A) were examined by bioinformatics analysis and RT-qPCR and western blot assays. Cell migratory ability was assessed through Transwell and wound healing assays. The angiogenic potential was evaluated by VEGF secretion, tube formation, and chick embryo chorioallantoic membrane (CAM) assays. The interaction between IGF2BP3 and HIF1A was explored using bioinformatics analysis and RIP and luciferase reporter assays. The results showed that IGF2BP3 and HIF1A were highly expressed in SC tissues and hypoxia-treated SC cells. IGF2BP3 knockdown inhibited hypoxia-induced cell migration and angiogenesis in SC. IGF2BP3 positively regulated HIF1A expression by directly binding to a specific m6A site in the coding region of HIF1A mRNA in SC cells. HIF1A overexpression abrogated the effects of IGF2BP3 knockdown on hypoxia-induced cell migration and angiogenesis in SC. In conclusion, IGF2BP3 knockdown inhibited hypoxia-induced cell migration and angiogenesis by down-regulating HIF1A in SC.

16.
Nano Lett ; 21(19): 7897-7904, 2021 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-34581586

RESUMEN

The fast spread of SARS-CoV-2 has severely threatened the public health. Establishing a sensitive method for SARS-CoV-2 detection is of great significance to contain the worldwide pandemic. Here, we develop a graphene field-effect transistor (g-FET) biosensor and realize ultrasensitive SARS-CoV-2 antibody detection with a limit of detection (LoD) down to 10-18 M (equivalent to 10-16 g mL-1) level. The g-FETs are modified with spike S1 proteins, and the SARS-CoV-2 antibody biorecognition events occur in the vicinity of the graphene surface, yielding an LoD of ∼150 antibodies in 100 µL full serum, which is the lowest LoD value of antibody detection. The diagnoses time is down to 2 min for detecting clinical serum samples. As such, the g-FETs leverage rapid and precise SARS-CoV-2 screening and also hold great promise in prevention and control of other epidemic outbreaks in the future.


Asunto(s)
Técnicas Biosensibles , COVID-19 , Grafito , Humanos , Límite de Detección , SARS-CoV-2
17.
Adv Ther ; 38(6): 2973-2989, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33881746

RESUMEN

INTRODUCTION: Metastatic prostate cancer (mPCa) is responsible for most prostate cancer (PCa) deaths worldwide. The present study aims to explore the molecular differences between mPCa and PCa. METHODS: The authors downloaded GSE6752, GSE6919, and GSE32269 from the Gene Expression Omnibus and employed integrated analysis to identify differentially expressed genes (DEGs) between mPCa and PCa. Functional and pathway-enrichment analyses were performed, and a protein-protein interaction (PPI) network and modules were constructed. Clinical mPCa specimens were collected to verify the results by performing RT-qPCR. The Cancer Genome Atlas database was used to conduct a survival analysis, and an immunohistochemical assay was performed. The invasion ability of PCa cells was verified by Transwell assay. RESULTS: One-hundred six consistently DEGs were found in mPCa compared with PCa. DEGs significantly enriched the positive regulation of cell proliferation, cell division, and cell adhesion in small cell lung cancer and PCa. Cell division, nucleoplasm, and cell cycle were selected from the PPI network, and the top 10 hub genes were selected. CDC20 and PTTG1 with genetic alterations were significantly associated with poorer disease-free survival. Immunohistochemical assay results showed that the expression levels of CDC20 and PTTG1 in mPCa were higher than those in PCa. The results of the migration assay indicated that CDC20 and PTTG1 could enhance the migration ability of PCa cells. CONCLUSION: The present study revealed that CDC20 and PTTG1 contribute more to migration, progression, and poorer prognoses in mPCa compared with PCa. CDC20 and PTTG1 could represent therapeutic targets in mPCa medical research and clinical studies.


Asunto(s)
Neoplasias Pulmonares , Neoplasias de la Próstata , Biomarcadores , Proteínas Cdc20/genética , Proteínas Cdc20/metabolismo , Biología Computacional , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Ontología de Genes , Humanos , Neoplasias Pulmonares/genética , Masculino , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/genética , Securina
18.
ACS Appl Mater Interfaces ; 13(17): 20448-20458, 2021 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-33899475

RESUMEN

Flexible pressure sensors have aroused tremendous attention, owing to their broad applications in healthcare, robotics, and prosthetics. So far, it remains a critical challenge to develop low-cost and controllable microstructures for flexible pressure sensors. Herein, a high-sensitivity and low-cost flexible piezoresistive sensor was developed by combining a controllable graphene-nanowalls (GNWs) wrinkle and a polydimethylsiloxane (PDMS) elastomer. For the GNWs-PDMS bilayer, the vertically grown GNWs film can effectively improve the interface strength and form delamination-free conformal wrinkles. More importantly, a controllable microstructure can be easily tuned through the thermal wrinkling method. The wrinkled graphene-nanowalls (WG) piezoresistive sensor has a high sensitivity (S = 59.0 kPa-1 for the 0-2 kPa region and S = 4.8 kPa-1 for the 2-20 kPa region), a fast response speed (<6.9 ms), and a low limit of detection (LOD) of 2 mg (∼0.2 Pa). The finite element method was used to analyze the working mechanism of the sensor, which revealed that the periods of the wrinkles play a dominant role in the performances of the sensors. These prominent merits enable wrinkled graphene sensors to successfully detect various signals from a weak stimulus to large pressures, for example, the detection of weak gas and plantar pressure. Furthermore, object manipulation, tactile imaging, and braille recognition applications have been demonstrated, showing their great potential in prosthetics limbs and intelligent robotics.

19.
Acc Chem Res ; 54(4): 1011-1022, 2021 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-33535000

RESUMEN

ConspectusSince the rise of two-dimensional (2D) materials, synthetic methods including mechanical exfoliation, solution synthesis, and chemical vapor deposition (CVD) have been developed. Mechanical exfoliation prepares randomly shaped materials with small size. Solution synthesis introduces impurities that degrade the performances. CVD is the most successful one for low-cost scalable preparation. However, when it comes to practical applications, disadvantages such as high operating temperature (∼1000 °C), probable usage of metal catalysts, contamination, defects, and interstices introduced by postgrowth transfer are not negligible. These are the reasons why plasma-enhanced CVD (PECVD), a method that enables catalyst-free in situ preparation at low temperature, is imperatively desirable.In this Account, we summarize our recent progress on controllable preparation of 2D materials by PECVD and their applications. We found that there was a competition between etching and nucleation and deposition in PECVD, making it highly controllable to obtain desired materials. Under different equilibrium states of the competition, various 2D materials with diverse morphologies and properties were prepared including pristine or nitrogen-doped graphene crystals, graphene quantum dots, graphene nanowalls, hexagonal boron nitride (h-BN), B-C-N ternary materials (BCxN), etc. We also used mild plasma to modify or treat 2D materials (e.g., WSe2) for desired properties.PECVD has advantages such as low temperature, transfer-free process, and industrial compatibility, which enable facile, scalable, and low-cost preparation of 2D materials with clean surfaces and interfaces directly on noncatalytic substrates. These merits significantly benefit the as-prepared materials in the applications. Field-effect transistors with high motilities were directly fabricated on graphene and nitrogen-doped graphene. By use of h-BN as the dielectric interfacial layer, both mobilities and saturated power densities of the devices were improved owing to the clean, closely contacted interface and enhanced interfacial thermal dissipation. High-quality materials and interfaces also enabled promising applications of these materials in photodetectors, pressure sensors, biochemical sensors, electronic skins, Raman enhancement, etc. To demonstrate the commercial applications, several prototypical devices were studied such as distributed pressure sensor arrays, touching module on a robot hand for braille recognition, and smart gloves for recording sign language. Finally, we discuss opportunities and challenges of PECVD as a comprehensive preparation methodology of 2D materials for future applications beyond traditional CVD.

20.
Molecules ; 26(2)2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33477737

RESUMEN

Phytohemagglutinin (PHA), the lectin purified from red kidney bean (Phaseolus vulgaris), is a well-known mitogen for human lymphocyte. Because it has obvious anti-proliferative and anti-tumor activity, PHA may serve as a potential antineoplastic drug in future cancer therapeutics. However, the literature is also replete with data on detrimental effects of PHA including oral toxicity, hemagglutinating activity, and immunogenicity. There is a critical need to evaluate the functional as well as the toxic components of PHAs to assist the rational designs of treatment with it. In this report, we performed SDS-PAGE to identify components of PHA-L, the tetrameric isomer of PHA with four identical L-type subunits, and then characterized biological function or toxicity of the major protein bands through in vitro experiments. It was found that the protein appearing as a 130 kD band in SDS-PAGE gel run under the condition of removal of ß-mercaptoethanol from the sample buffer together with omission of a heating step could inhibit tumor cell growth and stimulate lymphocyte proliferation, while most of the 35 kD proteins are likely non-functional impurity proteins and 15 kD protein may be related to hemolytic effect. Importantly, the 130 kD functional protein exhibits promising in vivo anti-tumor activity in B16-F10 melanoma C57 BL/6 mouse models, which may be achieved through potentiation of apoptosis and immunomodulation. Altogether, our results suggest that PHA-L prepared from crude extracts of red kidney bean by standard strategies is a mixture of many ingredients, and a 130 kD protein of PHA-L was purified and identified as the major functional component. Our study may pave the way for PHA-L as a potential anticancer drug.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis , Inmunomodulación , Lectinas/farmacología , Melanoma Experimental/tratamiento farmacológico , Phaseolus/química , Células A549 , Animales , Humanos , Melanoma Experimental/inmunología , Melanoma Experimental/patología , Ratones , Ratones Endogámicos C57BL
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